1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * linux/arch/arm/mm/cache-v4wt.S 4 * 5 * Copyright (C) 1997-2002 Russell king 6 * 7 * ARMv4 write through cache operations support. 8 * 9 * We assume that the write buffer is not enabled. 10 */ 11 #include <linux/linkage.h> 12 #include <linux/init.h> 13 #include <asm/assembler.h> 14 #include <asm/page.h> 15 #include "proc-macros.S" 16 17 /* 18 * The size of one data cache line. 19 */ 20 #define CACHE_DLINESIZE 32 21 22 /* 23 * The number of data cache segments. 24 */ 25 #define CACHE_DSEGMENTS 8 26 27 /* 28 * The number of lines in a cache segment. 29 */ 30 #define CACHE_DENTRIES 64 31 32 /* 33 * This is the size at which it becomes more efficient to 34 * clean the whole cache, rather than using the individual 35 * cache line maintenance instructions. 36 * 37 * *** This needs benchmarking 38 */ 39 #define CACHE_DLIMIT 16384 40 41 /* 42 * flush_icache_all() 43 * 44 * Unconditionally clean and invalidate the entire icache. 45 */ 46 ENTRY(v4wt_flush_icache_all) 47 mov r0, #0 48 mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache 49 ret lr 50 ENDPROC(v4wt_flush_icache_all) 51 52 /* 53 * flush_user_cache_all() 54 * 55 * Invalidate all cache entries in a particular address 56 * space. 57 */ 58 ENTRY(v4wt_flush_user_cache_all) 59 /* FALLTHROUGH */ 60 /* 61 * flush_kern_cache_all() 62 * 63 * Clean and invalidate the entire cache. 64 */ 65 ENTRY(v4wt_flush_kern_cache_all) 66 mov r2, #VM_EXEC 67 mov ip, #0 68 __flush_whole_cache: 69 tst r2, #VM_EXEC 70 mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache 71 mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache 72 ret lr 73 74 /* 75 * flush_user_cache_range(start, end, flags) 76 * 77 * Clean and invalidate a range of cache entries in the specified 78 * address space. 79 * 80 * - start - start address (inclusive, page aligned) 81 * - end - end address (exclusive, page aligned) 82 * - flags - vma_area_struct flags describing address space 83 */ 84 ENTRY(v4wt_flush_user_cache_range) 85 sub r3, r1, r0 @ calculate total size 86 cmp r3, #CACHE_DLIMIT 87 bhs __flush_whole_cache 88 89 1: mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry 90 tst r2, #VM_EXEC 91 mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry 92 add r0, r0, #CACHE_DLINESIZE 93 cmp r0, r1 94 blo 1b 95 ret lr 96 97 /* 98 * coherent_kern_range(start, end) 99 * 100 * Ensure coherency between the Icache and the Dcache in the 101 * region described by start. If you have non-snooping 102 * Harvard caches, you need to implement this function. 103 * 104 * - start - virtual start address 105 * - end - virtual end address 106 */ 107 ENTRY(v4wt_coherent_kern_range) 108 /* FALLTRHOUGH */ 109 110 /* 111 * coherent_user_range(start, end) 112 * 113 * Ensure coherency between the Icache and the Dcache in the 114 * region described by start. If you have non-snooping 115 * Harvard caches, you need to implement this function. 116 * 117 * - start - virtual start address 118 * - end - virtual end address 119 */ 120 ENTRY(v4wt_coherent_user_range) 121 bic r0, r0, #CACHE_DLINESIZE - 1 122 1: mcr p15, 0, r0, c7, c5, 1 @ invalidate I entry 123 add r0, r0, #CACHE_DLINESIZE 124 cmp r0, r1 125 blo 1b 126 mov r0, #0 127 ret lr 128 129 /* 130 * flush_kern_dcache_area(void *addr, size_t size) 131 * 132 * Ensure no D cache aliasing occurs, either with itself or 133 * the I cache 134 * 135 * - addr - kernel address 136 * - size - region size 137 */ 138 ENTRY(v4wt_flush_kern_dcache_area) 139 mov r2, #0 140 mcr p15, 0, r2, c7, c5, 0 @ invalidate I cache 141 add r1, r0, r1 142 /* fallthrough */ 143 144 /* 145 * dma_inv_range(start, end) 146 * 147 * Invalidate (discard) the specified virtual address range. 148 * May not write back any entries. If 'start' or 'end' 149 * are not cache line aligned, those lines must be written 150 * back. 151 * 152 * - start - virtual start address 153 * - end - virtual end address 154 */ 155 v4wt_dma_inv_range: 156 bic r0, r0, #CACHE_DLINESIZE - 1 157 1: mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry 158 add r0, r0, #CACHE_DLINESIZE 159 cmp r0, r1 160 blo 1b 161 ret lr 162 163 /* 164 * dma_flush_range(start, end) 165 * 166 * Clean and invalidate the specified virtual address range. 167 * 168 * - start - virtual start address 169 * - end - virtual end address 170 */ 171 .globl v4wt_dma_flush_range 172 .equ v4wt_dma_flush_range, v4wt_dma_inv_range 173 174 /* 175 * dma_unmap_area(start, size, dir) 176 * - start - kernel virtual start address 177 * - size - size of region 178 * - dir - DMA direction 179 */ 180 ENTRY(v4wt_dma_unmap_area) 181 add r1, r1, r0 182 teq r2, #DMA_TO_DEVICE 183 bne v4wt_dma_inv_range 184 /* FALLTHROUGH */ 185 186 /* 187 * dma_map_area(start, size, dir) 188 * - start - kernel virtual start address 189 * - size - size of region 190 * - dir - DMA direction 191 */ 192 ENTRY(v4wt_dma_map_area) 193 ret lr 194 ENDPROC(v4wt_dma_unmap_area) 195 ENDPROC(v4wt_dma_map_area) 196 197 .globl v4wt_flush_kern_cache_louis 198 .equ v4wt_flush_kern_cache_louis, v4wt_flush_kern_cache_all 199 200 __INITDATA 201 202 @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S) 203 define_cache_functions v4wt 204